IAEA SAFETY STANDARDS SERIES

Transcription

1 IAEA SAFETY STANDARDS SERIES Commissioning for Nuclear Power Plants SAFETY GUIDE No. NS-G-2.9 INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA

2 IAEA SAFETY RELATED PUBLICATIONS IAEA SAFETY STANDARDS Under the terms of Article III of its Statute, the IAEA is authorized to establish standards of safety for protection against ionizing radiation and to provide for the application of these standards to peaceful nuclear activities. The regulatory related publications by means of which the IAEA establishes safety standards and measures are issued in the IAEA Safety Standards Series. This series covers nuclear safety, radiation safety, transport safety and waste safety, and also general safety (that is, of relevance in two or more of the four areas), and the categories within it are Safety Fundamentals, Safety Requirements and Safety Guides. Safety Fundamentals (blue lettering) present basic objectives, concepts and principles of safety and protection in the development and application of nuclear energy for peaceful purposes. Safety Requirements (red lettering) establish the requirements that must be met to ensure safety. These requirements, which are expressed as shall statements, are governed by the objectives and principles presented in the Safety Fundamentals. Safety Guides (green lettering) recommend actions, conditions or procedures for meeting safety requirements. Recommendations in Safety Guides are expressed as should statements, with the implication that it is necessary to take the measures recommended or equivalent alternative measures to comply with the requirements. The IAEA s safety standards are not legally binding on Member States but may be adopted by them, at their own discretion, for use in national regulations in respect of their own activities. The standards are binding on the IAEA in relation to its own operations and on States in relation to operations assisted by the IAEA. Information on the IAEA s safety standards programme (including editions in languages other than English) is available at the IAEA Internet site or on request to the Safety Co-ordination Section, IAEA, P.O. Box 100, A-1400 Vienna, Austria. OTHER SAFETY RELATED PUBLICATIONS Under the terms of Articles III and VIII.C of its Statute, the IAEA makes available and fosters the exchange of information relating to peaceful nuclear activities and serves as an intermediary among its Member States for this purpose. Reports on safety and protection in nuclear activities are issued in other series, in particular the IAEA Safety Reports Series, as informational publications. Safety Reports may describe good practices and give practical examples and detailed methods that can be used to meet safety requirements. They do not establish requirements or make recommendations. Other IAEA series that include safety related publications are the Technical Reports Series, the Radiological Assessment Reports Series, the INSAG Series, the TECDOC Series, the Provisional Safety Standards Series, the Training Course Series, the IAEA Services Series and the Computer Manual Series, and Practical Radiation Safety Manuals and Practical Radiation Technical Manuals. The IAEA also issues reports on radiological accidents and other special publications.

3 COMMISSIONING FOR NUCLEAR POWER PLANTS

4 The following States are Members of the International Atomic Energy Agency: AFGHANISTAN ALBANIA ALGERIA ANGOLA ARGENTINA ARMENIA AUSTRALIA AUSTRIA AZERBAIJAN BANGLADESH BELARUS BELGIUM BENIN BOLIVIA BOSNIA AND HERZEGOVINA BOTSWANA BRAZIL BULGARIA BURKINA FASO CAMEROON CANADA CENTRAL AFRICAN REPUBLIC CHILE CHINA COLOMBIA COSTA RICA CÔTE D IVOIRE CROATIA CUBA CYPRUS CZECH REPUBLIC DEMOCRATIC REPUBLIC OF THE CONGO DENMARK DOMINICAN REPUBLIC ECUADOR EGYPT EL SALVADOR ERITREA ESTONIA ETHIOPIA FINLAND FRANCE GABON GEORGIA GERMANY GHANA GREECE GUATEMALA HAITI HOLY SEE HONDURAS HUNGARY ICELAND INDIA INDONESIA IRAN, ISLAMIC REPUBLIC OF IRAQ IRELAND ISRAEL ITALY JAMAICA JAPAN JORDAN KAZAKHSTAN KENYA KOREA, REPUBLIC OF KUWAIT LATVIA LEBANON LIBERIA LIBYAN ARAB JAMAHIRIYA LIECHTENSTEIN LITHUANIA LUXEMBOURG MADAGASCAR MALAYSIA MALI MALTA MARSHALL ISLANDS MAURITIUS MEXICO MONACO MONGOLIA MOROCCO MYANMAR NAMIBIA NETHERLANDS NEW ZEALAND NICARAGUA NIGER NIGERIA NORWAY PAKISTAN PANAMA PARAGUAY PERU PHILIPPINES POLAND PORTUGAL QATAR REPUBLIC OF MOLDOVA ROMANIA RUSSIAN FEDERATION SAUDI ARABIA SENEGAL SERBIA AND MONTENEGRO SEYCHELLES SIERRA LEONE SINGAPORE SLOVAKIA SLOVENIA SOUTH AFRICA SPAIN SRI LANKA SUDAN SWEDEN SWITZERLAND SYRIAN ARAB REPUBLIC TAJIKISTAN THAILAND THE FORMER YUGOSLAV REPUBLIC OF MACEDONIA TUNISIA TURKEY UGANDA UKRAINE UNITED ARAB EMIRATES UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND UNITED REPUBLIC OF TANZANIA UNITED STATES OF AMERICA URUGUAY UZBEKISTAN VENEZUELA VIETNAM YEMEN ZAMBIA ZIMBABWE The Agency s Statute was approved on 23 October 1956 by the Conference on the Statute of the IAEA held at United Nations Headquarters, New York; it entered into force on 29 July The Headquarters of the Agency are situated in Vienna. Its principal objective is to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world. IAEA, 2003 Permission to reproduce or translate the information contained in this publication may be obtained by writing to the International Atomic Energy Agency, Wagramer Strasse 5, P.O. Box 100, A-1400 Vienna, Austria. Printed by the IAEA in Austria June 2003 STI/PUB/1152

5 SAFETY STANDARDS SERIES No. NS-G-2.9 COMMISSIONING FOR NUCLEAR POWER PLANTS SAFETY GUIDE INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA, 2003

6 IAEA Library Cataloguing in Publication Data Commissioning for nuclear power plants : safety guide. Vienna : International Atomic Energy Agency, p. ; 24 cm. (Safety standards series, ISSN X ; no. NS-G-2.9) STI/PUB/1152 ISBN Includes bibliographical references. 1. Nuclear power plants Safety measures. 2. Nuclear power plants testing. 3. Nuclear fuels. 4. Loading and unloading Safety measures. I. International Atomic Energy Agency. II. Series. IAEAL

7 FOREWORD by Mohamed ElBaradei Director General One of the statutory functions of the IAEA is to establish or adopt standards of safety for the protection of health, life and property in the development and application of nuclear energy for peaceful purposes, and to provide for the application of these standards to its own operations as well as to assisted operations and, at the request of the parties, to operations under any bilateral or multilateral arrangement, or, at the request of a State, to any of that State s activities in the field of nuclear energy. The following bodies oversee the development of safety standards: the Commission on Safety Standards (CSS); the Nuclear Safety Standards Committee (NUSSC); the Radiation Safety Standards Committee (RASSC); the Transport Safety Standards Committee (TRANSSC); and the Waste Safety Standards Committee (WASSC). Member States are widely represented on these committees. In order to ensure the broadest international consensus, safety standards are also submitted to all Member States for comment before approval by the IAEA Board of Governors (for Safety Fundamentals and Safety Requirements) or, on behalf of the Director General, by the Publications Committee (for Safety Guides). The IAEA s safety standards are not legally binding on Member States but may be adopted by them, at their own discretion, for use in national regulations in respect of their own activities. The standards are binding on the IAEA in relation to its own operations and on States in relation to operations assisted by the IAEA. Any State wishing to enter into an agreement with the IAEA for its assistance in connection with the siting, design, construction, commissioning, operation or decommissioning of a nuclear facility or any other activities will be required to follow those parts of the safety standards that pertain to the activities to be covered by the agreement. However, it should be recalled that the final decisions and legal responsibilities in any licensing procedures rest with the States. Although the safety standards establish an essential basis for safety, the incorporation of more detailed requirements, in accordance with national practice, may also be necessary. Moreover, there will generally be special aspects that need to be assessed on a case by case basis. The physical protection of fissile and radioactive materials and of nuclear power plants as a whole is mentioned where appropriate but is not treated in detail; obligations of States in this respect should be addressed on the basis of the relevant instruments and publications developed under the auspices of the IAEA. Nonradiological aspects of industrial safety and environmental protection are also not explicitly considered; it is recognized that States should fulfil their international undertakings and obligations in relation to these.

8 The requirements and recommendations set forth in the IAEA safety standards might not be fully satisfied by some facilities built to earlier standards. Decisions on the way in which the safety standards are applied to such facilities will be taken by individual States. The attention of States is drawn to the fact that the safety standards of the IAEA, while not legally binding, are developed with the aim of ensuring that the peaceful uses of nuclear energy and of radioactive materials are undertaken in a manner that enables States to meet their obligations under generally accepted principles of international law and rules such as those relating to environmental protection. According to one such general principle, the territory of a State must not be used in such a way as to cause damage in another State. States thus have an obligation of diligence and standard of care. Civil nuclear activities conducted within the jurisdiction of States are, as any other activities, subject to obligations to which States may subscribe under international conventions, in addition to generally accepted principles of international law. States are expected to adopt within their national legal systems such legislation (including regulations) and other standards and measures as may be necessary to fulfil all of their international obligations effectively. EDITORIAL NOTE An appendix, when included, is considered to form an integral part of the standard and to have the same status as the main text. Annexes, footnotes and bibliographies, if included, are used to provide additional information or practical examples that might be helpful to the user. The safety standards use the form shall in making statements about requirements, responsibilities and obligations. Use of the form should denotes recommendations of a desired option. The English version of the text is the authoritative version.

9 CONTENTS 1. INTRODUCTION Background ( ) Objective ( ) Scope (1.5) Structure (1.6) COMMISSIONING PROGRAMME General ( ) Main aspects of the commissioning programme ( ) Testing in the commissioning programme ( ) Review and approval ( ) STAGES OF COMMISSIONING General ( ) Pre-operational tests ( ) Fuel loading and subcritical tests ( ) Initial criticality and low power tests ( ) Power tests ( ) ORGANIZATION AND MANAGEMENT Commissioning organization ( ) Functions and responsibilities in commissioning activities ( ) Interfaces between participants in the commissioning process ( ) Assessment ( ) Qualification and training ( ) Maintenance during commissioning ( ) Plant handover ( ) Quality assurance ( ) Emergency arrangements ( ) Feedback of experience from commissioning ( )

10 5. IMPLEMENTATION OF THE COMMISSIONING PROGRAMME Test procedures ( ) Test results ( ) Initial fuel loading ( ) Achieving initial criticality ( ) Deviations during commissioning ( ) DOCUMENTATION ( ) APPENDIX: FUEL LOADING ANNEX: DETAILED LISTING OF COMMISSIONING TESTS REFERENCES GLOSSARY CONTRIBUTORS TO DRAFTING AND REVIEW BODIES FOR THE ENDORSEMENT OF SAFETY STANDARDS

11 1. INTRODUCTION BACKGROUND 1.1. This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. It supplements and elaborates on Section 5 of Safety of Nuclear Power Plants: Operation [1] on safety requirements for the commissioning of nuclear power plants. This Safety Guide is a revision of the IAEA Safety Guide on Commissioning Procedures for Nuclear Power Plants which was issued in 1980 as Safety Series No. 50-SG-O The revision of the Safety Series publication No. 50-SG-O4 was conducted in accordance with the following: (a) (b) (c) (d) (e) The technical content of the original Safety Guide was kept in its entirety and updated where necessary. Additional material resulting from recent experience in the area of commissioning was included. The text was restructured to be in accordance with the logic of the approach followed in commissioning a nuclear power plant. The Safety Guide is applicable to any type of power plant based on a thermal nuclear reactor but it is not meant to substitute for the detailed technical procedures to be made available at the plant for the purposes of its commissioning. The Appendix provides guidance on the procedures to be carried out for fuel loading and the Annex elaborates on the tests to be considered for commissioning. OBJECTIVE 1.3. The objective of this Safety Guide is to make recommendations based on international good practices in commissioning for nuclear power plants, as currently followed in Member States, which will enable commissioning to proceed safely and to a high quality. It will also enable the necessary assurances to be provided that the plant has been constructed in accordance with the design intent and can be operated safely Some or all of this Safety Guide may be relevant when a nuclear power plant is to be restarted after an extended shutdown period. Where extensive modifications 1

12 have been made to an existing nuclear power plant, the commissioning of these modifications and their integration into the plant may require comprehensive tests to demonstrate that the plant meets the original or the modified design requirements. The commissioning of modifications is covered in Ref. [2]; however, all or part of this Safety Guide may be used. SCOPE 1.5. This Safety Guide deals with the commissioning of land based stationary thermal nuclear power plants of all types. It covers how the requirements of the commissioning programme, organization and management, test and review procedures and the interfaces can be met between organizations involved in the commissioning activities. It also deals with the control of changes in the commissioning programme and with the documentation required and produced in commissioning. STRUCTURE 1.6. Section 2 relates to the entire commissioning programme. General matters as well as recommendations for the preparation and approval of the commissioning programme are discussed. Section 3 covers different stages of commissioning in accordance with the practices commonly adopted by States. Organizational matters of the commissioning process are presented in Section 4. The responsibilities of the parties involved in the commissioning process, the interfaces between them, safety management, qualification of the commissioning personnel and organizational aspects of plant handover are covered. Section 5 presents practical issues relating to the implementation of the commissioning programme. Different aspects of the testing which forms the core of the commissioning programme are discussed. The initial fuel loading as well as the achievement of initial criticality are dealt with. Section 6 deals with the documentation to be prepared and produced in commissioning. The Appendix presents specific items to be included in the procedures for fuel loading. The Annex gives a detailed listing of commissioning tests. 2

13 2. COMMISSIONING PROGRAMME GENERAL 2.1. Commissioning, being essential to the subsequent safe operation of the plant, should be carefully planned and executed. The results of commissioning should demonstrate that the requirements and intents of the design and the intent of the designers as stated in the safety analysis report have been met. They should also define the initial characteristics of systems and equipment and provide the source values for operational periodic tests The commissioning should cover all the activities to be performed on structures, systems and components to bring them to an operating mode. It should verify the provisions of the design basis and confirm the assumptions made in the safety analysis report. It should also ensure that there are adequate margins between the design and safety requirements and the actual performance. The commissioning programme may include tests of different types and distinctions should be made between: (a) (b) (c) (d) (e) Tests which aim at the verification of each functional system including its overall performance. Tests on new types of equipment. Tests performed on the prototype plant for a series in order to test the validity of a new concept; subsequent tests on the plants in the series would then just test for conformity. Tests aimed at acquiring data to validate the code used for the design and to confirm the validity of the limiting safety system settings [3]. Tests to validate operating procedures A detailed programme of commissioning activities should be prepared and responsibilities for implementing and reporting on the various parts of the commissioning programme should be clearly defined. In the planning for commissioning, all activities and organizations involved should be taken into consideration Adequate provision should be made for the allocation of responsibilities for safety at different stages of the commissioning programme, especially after the arrival of fuel at the site. The commissioning programme should indicate the principal points at which reviews and hold points are necessary to satisfy both the operating organization and the regulatory body. 3

14 2.5. During commissioning, normal operating procedures, including those for operational periodic tests, should be widely used to validate the applicability of these procedures. The emergency operating procedures (EOPs), which are not used in routine commissioning operations, should also be validated in the commissioning programme, to the extent possible Close liaison should be maintained between the regulatory body and the operating organization throughout the development and implementation of the whole commissioning programme. MAIN ASPECTS OF THE COMMISSIONING PROGRAMME 2.7. The commissioning programme should be comprehensive and detailed so as to enable assurances to be given that the plant will be commissioned in a safe, efficient and auditable manner. For multiunit plants a separate programme should be produced for each unit. The commissioning programme should separately identify all the tests and related activities necessary to demonstrate that the plant has been properly designed and constructed and can be operated safely The programme should be divided into stages whose number and size will depend upon safety requirements and technical and administrative requirements. The programme should show the planned duration of the activities and their interrelationships, and should include activities that may be necessary in order to provide opportunities for the operating personnel to gain familiarity with the operation of the plant The commissioning programme should be structured so as to ensure that the following objectives are met: (a) (b) (c) (d) All the tests necessary to demonstrate that the installed plant meets the design intent stated in the safety analysis report are performed. The tests are performed in a systematic sequence: in particular, tests should be arranged to be progressive, so that the plant is exposed to less onerous conditions before more onerous ones. The programme provides means of identifying hold points in the commissioning process. Operating personnel are trained and procedures are validated The programme should also include: 4

15 (1) The points at which reviews and hold points are required. (2) Any applicable requirements of the regulatory body, including the witnessing of specified tests. (3) The title of each test together with a unique identification. (4) Cross-references to other documents relevant to commissioning. (5) Provision for data collection for further use The commissioning programme should include provisions to ensure that operating and maintenance personnel in all disciplines participate to the extent possible in commissioning activities and that the operating procedures are validated to the extent practicable with the participation of plant staff. Designers and other specialists should be involved in formulating tests The programme should provide a framework for the scheduling of tests and related activities, and for suitable personnel and equipment to be available at the proper time. The programme should also provide for the timely production of all documentation The commissioning programme should be written in such a form as to enable the objectives and methods of testing to be readily understood by all concerned and to allow control and co-ordination by management The commissioning programme should be prepared in accordance with the quality assurance programme, as recommended in Safety Series No. 50-C/SG-Q on Quality Assurance for Safety in Nuclear Power Plants and other Nuclear Installations [4]. TESTING IN THE COMMISSIONING PROGRAMME Testing, as the core of the commissioning programme, should be sufficiently comprehensive to establish that the plant can operate in all modes for which it has been designed to operate. However, tests should not be conducted and operating modes or plant configurations should not be established if they have not been analysed, if they fall outside the range of assumptions made in analysing postulated accidents in the safety analysis report, or if they might damage the plant or jeopardize safety In determining the sequence of testing, the following points should be carefully considered: 5

16 (a) (b) (c) Certain systems should undergo prior testing so that they are available for the proper testing of other systems; Certain systems should be operational to ensure that other systems can be tested without jeopardizing personnel, the plant or nuclear safety; At any given stage, those tests which are to be considered should be grouped together and completed before the commissioning programme can safely continue The specific procedures should be written in the commissioning programme and should describe the principles, objectives and nature of the tests. They should include the criteria for judging the validity of the results and the acceptance criteria. These procedures for systems important for safety should contain checks that all performance levels and operating parameters have been demonstrated for all the operating configurations (normal, transient and accident conditions) The commissioning programme should be comprehensive, including statutory non-nuclear tests according to national practice, and should have sufficient scope for redundancy in testing to ensure that there have been no omissions in testing complex systems For identical units in a multiunit nuclear power plant and/or for series of identical plants, it may be acceptable to omit selected tests from those already performed for the units tested previously. The operating organization should ensure that such an action does not jeopardize safety and that it is taken only with the prior approval of the regulatory body If some of the structures, systems and components are common to more than one unit, tests should be conducted to provide assurance that the specified performance requirements of these structures, systems and components can be met for the design intent of each unit Special provision should be made to ensure that the safety of a unit already in operation is not jeopardized in the commissioning tests. Such provisions should include conducting a hazard assessment and obtaining the prior approval of the regulatory body and specific written approval from the manager responsible for the operating unit. 6

17 REVIEW AND APPROVAL Whatever the organizational arrangements for commissioning of a nuclear power plant, the operating organization should review and approve the commissioning programme The commissioning programme should be submitted for review and approval to the regulatory body, in accordance with national practice. 3. STAGES OF COMMISSIONING GENERAL 3.1. The commissioning programme of a nuclear power plant should be divided into stages. A review of the test results of each stage should be completed before continuing to the next stage. The review should enable a judgement to be made on whether the commissioning programme should continue to the next stage, and whether the succeeding stages should be modified as a consequence of the test results or because some tests in the stage had not been undertaken or had not been completed. (The Annex provides a detailed list of tests to be considered in developing the commissioning programme.) 3.2. On the basis of the broad range of commissioning practices in States, the commissioning process can be divided into the following stages: pre-operational tests fuel loading and subcritical tests initial criticality and low power tests power tests In addition, if the sequence of tests in a stage of commissioning is significant for safety, substages may be required by the operating organization or regulatory body 1. 1 For example in heavy water reactors, the primary heat transport system (and moderator system) may be first commissioned with light water followed by hot conditioning of the inner surfaces of carbon steel piping. The light water is then drained and the system dried thoroughly before the addition of heavy water. 7

18 Each stage and substage should be followed by a review before the next stage is started. Before the start of initial criticality tests, low power tests and power tests all the tests at the previous stages should be completed The sequence of tests within each substage should be given in the chronological order in which they are expected to be performed Each stage should include the tasks necessary for the preparation of the succeeding stage and in particular the availability requirements of the systems for the succeeding stage To the extent practicable, the tests should be of sufficient duration to allow the systems and components under test to reach their normal equilibrium conditions, thus reducing the probability of failure in the early stages of operation Careful consideration should be given to the demonstration of the capability of the systems and components to withstand failures and/or malfunctions that previous experience has shown may occur over the expected plant lifetime The relevant safety system settings and alarm settings, including those of radiological protection instruments, should be specified at the appropriate commissioning stages. PRE-OPERATIONAL TESTS General 3.9. Before the commencement of the initial testing of any structure, system or component the following steps should be taken: (a) (b) (c) Construction activities associated with the system, including quality assurance, should be completed and documented to the extent necessary and practicable. It should be ensured that the equipment is ready for operation: inspection for proper fabrication (including welding) and cleanness, checking of electrical and protective devices, adjustment of settings on valve torque limiting devices, calibration of instruments, verification of operability of instrument loops and required response times, adjustment and settings of process controllers and limit switches. It should be ensured that test equipment is operable and properly calibrated and that response times are as required. 8

19 3.10. A review should therefore be undertaken before the commencement of this stage to ensure that the tests have been carried out on those systems and components required for this stage for which the construction group is responsible (para. 4.27). The tests should ensure that the construction is of the appropriate quality and that the equipment is in a fit state for commissioning to be started A satisfactory pre-operational test should take into account the proper sequence of tests of electrical systems, instrumentation systems and other service systems such as cooling water systems and fire protection systems in order to ensure the availability of the necessary services for the implementation of the entire commissioning programme The stages of the pre-operational tests may be divided into the following substages: cold performance tests hot performance tests. Any required pre-service inspections should be performed during or at the end of these stages. Cold performance tests Cold performance tests include the initial startup of fluid systems and support systems. The objective of this stage is to obtain initial operational data on equipment, ensure compatibility of operation with interfacing systems and verify the functional performance of these systems. The tests usually include pressure testing of the primary and secondary systems Where a pressure test required by regulations is not carried out before the transfer of the system to the commissioning group, it should be carried out as part of the commissioning programme in this substage. Hot performance tests Hot performance tests should be undertaken to verify the conformance of systems with specified requirements. Where possible, these tests should follow cold performance tests, simulating as far as practicable plant operating conditions, including anticipated operational occurrences at typical temperatures, pressures and flow rates. 9

20 3.16. The tests should, to the extent possible, verify the effectiveness of heat insulation and heat removal systems. They will enable initial checking of flow rates, vibration, clearances and other provisions made for accommodating the thermal expansion of components or systems. The operation of instruments and other equipment at high temperature should be verified and the relevant operating techniques should be confirmed The duration of hot performance testing should be such that a steady state operating condition is achieved, in order to determine whether the structures, systems and components are operating according to specifications The operating personnel should take the opportunity at this substage to use and verify the operating procedures. FUEL LOADING AND SUBCRITICAL TESTS The purpose of the stage of fuel loading and subcritical tests is to ensure that the fuel is loaded into the reactor safely in accordance with the loading pattern precalculated in the design. In addition, at this stage it should be confirmed that the reactor is in a suitable condition to be started up and that all prerequisites for permitting the reactor to go critical have been met (see also the Appendix) With the core loaded and the reactor maintained in a subcritical condition, a series of performance tests should be carried out. These should include checks on coolant flow rates, instrumentation, rod control mechanisms, automatic rod insertion and other important features of the primary circuit The beginning of initial fuel loading is the commencement of operation; from this point onwards the relevant safety requirements for plant operation apply [1]. Responsibility for meeting these safety requirements should usually rest from this juncture with the plant manager. INITIAL CRITICALITY AND LOW POWER TESTS At the stage of initial criticality and low power tests, the initial criticality of the loaded core is achieved for the first time. The subsequent low power tests should be carried out to confirm that: 10

21 (a) (b) (c) The performance of the reactor core is commensurate with predictions made in the core design. The reactor core is in a proper condition for operation at higher power levels and the characteristics of the reactor core coolant, reactivity control systems and shielding are appropriate. The reactor physics parameters are in accordance with predictions made in the design. In order to permit power testing, assurance should first be obtained on the basis of the information gained from these tests that there is no serious discrepancy between measured values of reactor physics parameters and other parameters and values used in the safety analysis report. The power levels at this stage should be the lowest that give reliable and stable measurements and which enable the conditions required to perform the specified tests to be achieved. Special startup instrumentation should be provided if necessary Where necessitated by the reactor design, system flow tests and cold and hot tests of appropriate duration should be made with the loaded core. Appropriate tests of fuel handling equipment should be completed and radiological surveys and functional tests of radiation protection equipment should be made In these tests the trip limits of the nuclear flux channel for the reactor protection system should be set to a conservative level. POWER TESTS A comprehensive range of power tests should be made to confirm that the plant can be operated in accordance with the design intent and that the plant can continue to be operated in a safe manner. Those tests that are necessary to demonstrate safe operability should be completed without delay. This stage should in general be limited to those tests which can be carried out only at power This stage of commissioning consists of a step by step approach to full power and full power tests. At each substage a series of tests will be carried out at specified power levels. Typical steps may be 10, 25, 50, 75, 90 and 100% of full power Tests should be made to demonstrate to the extent practicable that the plant operates in accordance with the design both in steady state conditions and during and after anticipated operational occurrences, including reactor trips and load rejections initiated at appropriate power levels. 11

22 3.28. A review should be carried out at the end of the stage to confirm whether the operational limits and conditions are adequate and practicable [3], and to identify any constraints on the operation of the plant that the commissioning tests have shown to be necessary. 4. ORGANIZATION AND MANAGEMENT COMMISSIONING ORGANIZATION Organizational arrangements 4.1. Organizational arrangements should be in place to achieve the safety objectives of commissioning in accordance with the programme outlined in Section 2. They should represent a convenient and practical working scheme which allows optimum use of available personnel, materials and methods, and which enables assurances on safety to be obtained The principal activities performed in commissioning may be divided into three categories: (1) Those associated with the final stage of construction and installation of the plant; (2) Those specific to commissioning, including safety reviews; (3) Those associated with the operation of the plant Accordingly, personnel performing the above activities may belong to the following groups: construction group commissioning group operating group There may be other representatives participating in commissioning activities, such as representatives of the designers, the construction group, the manufacturers and the regulatory body. These representatives should collaborate with the aforementioned groups as appropriate. In particular, the designers and manufacturers should provide adequate and complete information to the groups. The designers 12

23 should also review the commissioning data and should certify that the performance meets the design intent There may be many ways in which the construction, commissioning and operating groups could be formed by different organizations. This may depend upon the industrial practice and experience of nuclear power in the State, upon contractual arrangements, as well as upon the physical size and design of the plant. The composition of the groups may also be influenced by the availability and experience of personnel performing specialized functions. If the operating organization decides to contract the commissioning activities to another organization, it should be made clear that the ultimate responsibility for safety remains with the operating organization The construction group should ensure that the installation has been completed in accordance with specifications. The commissioning group should ensure that structures, systems and components are tested to provide assurance that the plant has been properly designed and constructed and is ready for safe operation. The operating group should operate systems and plant in accordance with the assumptions and intent of the commissioning programme The working arrangements should, as far as practicable, make use of the operating personnel so that they become familiar with the plant and the facilities during commissioning. In addition, the operating group should participate in the commissioning activities in order to ensure that as many operating personnel as possible gain field experience and to establish an institutional memory of the plant Since construction, commissioning and operating activities overlap, in the arrangements made in respect of utilization of personnel among the construction, commissioning and operating groups, it should be ensured that responsibilities remain clear at all times. Safety management 4.9. The commissioning phase should foster a safety culture [5], which should be maintained throughout the operating phase Specific consideration should be given to the arrangements used by the organizations participating in the commissioning process for the management of safety [6] in order to enhance safety culture and achieve good safety performance. Safety management should comprise all aspects of safety, such as industrial safety, fire protection, radiation protection and nuclear safety. 13

24 4.11. The following specific aspects should be reflected in the safety management system for the commissioning phase: (a) (b) (c) (d) The interface and appropriate links to ensure that commissioning is in accordance with the requirements of the safety analysis report; The interface between the various organizations participating in the commissioning process; The transfer of the responsibility for safety from one participating organization to another; The discharge of responsibilities for safety owing to the gradual handover of commissioned systems and components of the plant. Organization of the commissioning group The commissioning group and the special arrangements made to ensure proper co-ordination of commissioning activities should be established early enough to allow all these activities to be identified and adequate preparations to be made The commissioning group should be headed by a commissioning manager who has had experience with nuclear power plants. The commissioning manager should be appointed well in advance of the actual commissioning work so as to be able to make the necessary arrangements for scheduling and organizing work units, work plans and other resources Specific test teams should be established to perform commissioning tests. The number and composition of these teams should be dependent on matters such as: the number and complexity of the systems to be tested the scheduled target dates the workload the skills necessary to perform the tests the staff available Each test team should be led by a test team leader with appropriate experience The commissioning manager should prepare suborganizational charts showing the allocation of responsibilities for staffing and systems to each test team leader. These charts should be made available to the other groups in order to help ensure effective co-ordination of the work. 14

25 4.17. A planning and scheduling unit should be set up in the commissioning group to monitor and report on the progress of commissioning in all its aspects, including the issuing of commissioning reports and transfer certificates for systems. FUNCTIONS AND RESPONSIBILITIES IN COMMISSIONING ACTIVITIES General Responsibility for commissioning activities may be assigned to a contractor, the construction organization or the operating organization. In some cases responsibility may be transferred from one organization to another at the time of fuel loading or at some other appropriate hold point. Whatever the arrangement, the organization or individual responsible for commissioning should be accountable to the organization or individual responsible for compliance with the licence for the following: (a) (b) (c) Demonstration that the plant behaves in accordance with the design intent, Confirmation that the plant has been tested within the design limits only, Ensuring that safety requirements are observed while the commissioning process is being conducted The detailed listing of functions and responsibilities in paras should be viewed as illustrative only; actual functional responsibilities may be assigned according to national regulations and practice. Operating organization The operating organization, as the organization authorized by the regulatory body to operate the plant, should be the overall controlling and co-ordinating authority for overseeing the safe and satisfactory completion of all commissioning work When commissioning activities are conducted under the responsibility of the contractors, the operating organization should make the necessary arrangements to review and approve these activities at all stages Appropriate actions should be taken by the operating organization at the commissioning stage to promote and foster the development of safety culture at the plant. Attributes such as personal dedication, safety consciousness and a questioning attitude should be fostered at the pre-operational phase so as to become habitual in the subsequent operational stage. 15

26 4.23. The responsibilities of the operating organization should include: (a) (b) (c) (d) (e) (f) To control, review and co-ordinate the activities of the construction, commissioning and operating groups in an effective manner; To ensure that the commissioning procedures are prepared, reviewed and approved by personnel with appropriate technical backgrounds and experience; To arrange for the required submissions to the regulatory body at the approved stages and to comply with its requirements; To establish procedures for ensuring the co-ordination of commissioning activities, account being taken of the views and experience of members of the construction, commissioning and operating groups as well as other participants such as those from the designers, the manufacturers and the consultants and quality assurance personnel; To ensure the maintenance of adequate numbers of properly trained, experienced, qualified and, where required, authorized personnel in the construction, commissioning and operating groups; To receive and disseminate the requirements of and information from the regulatory body In discharging these responsibilities, various methods may be adopted by the management of the operating organization. The essential tasks in achieving the necessary co-ordination are as follows: To review and approve the commissioning programme; To co-ordinate the provision of the personnel, materials and equipment necessary for commissioning; To identify and monitor the transfers of responsibilities; To monitor the implementation of the commissioning programme; To resolve problems between groups and interface problems; To review and approve test procedures; To consider the safety aspects of proposed changes; To determine whether tests and stages have been properly completed; To remedy those defects detected in commissioning tests; To maintain liaison with the regulatory body according to national regulations and practice. Operating group The responsibilities of the operating personnel at the plant in relation to commissioning should be as follows: 16

27 To satisfy themselves that the systems which are transferred comply with specified performance requirements, the design intent and safety requirements; To accept responsibility for the transferred systems; To participate in the commissioning activities; To become competent in the methods of operation of the plant; To carry out operation and maintenance with competent staff using approved techniques to meet the needs of the commissioning programme. Commissioning group The responsibilities of the commissioning group should include the following: To plan in advance the commissioning programme with detailed test sequences, time schedules and staffing requirements; To update the commissioning programme in the light of experience in commissioning and as a result of design modifications; To establish a procedure for the preparation, review and approval of test procedures and other procedures; To ensure that operational flow sheets, operating and maintenance instructions, commissioning procedures, formats for commissioning reports and test reports, plant handover documents and submissions to the regulatory body are available; To establish a procedure for the systematic recording of plant data for future use; To establish a procedure for ensuring that incidents in commissioning are analysed so that the experience gained can be fed back to the designers or the operating group; To verify that the installation of structures, systems and components has been satisfactorily completed and codified for proper identification; To ensure that the prerequisites for the commissioning programme have been satisfied and that pre-operational tests such as functional checks, logic checks, interlock checks and system integrity checks have been completed; To ensure that the commissioning procedures comply with the appropriate rules and regulations for safety (including radiological protection and safety); To ensure that the systems are commissioned safely and to confirm that the written operating procedures are adequate; To implement all the tests in the commissioning programme, including repeat testing of the systems that have been commissioned initially as partially installed; To make suitable arrangements for testing and maintaining systems (particularly safety related items) for which responsibility has been accepted; 17

28 To direct the operation of systems in the commissioning programme and to update operational flow sheets and operating and maintenance instructions, as well as procedures based on experience in commissioning; To issue commissioning reports on tests; To ensure that a procedure is in place to control the calibration of test and measurement equipment; To establish a procedure to ensure that all participants in the commissioning process are suitably qualified and experienced; To ensure the configuration management, maintaining consistency between asbuilt drawings and procedures and physical configuration and the design requirements; To ensure that design changes are requested, reviewed and implemented when design criteria are not met or when they fall short; To establish a procedure for controlling temporary changes to plant and equipment; To issue test certificates and stage completion certificates or their equivalent; To provide up to date baseline information to the operating group and the operating organization; To report to the operating organization any deficiency detected in commissioning tests in order that corrective actions can be taken; To maintain a record of limiting conditions in commissioning; To ensure that plant performance is in accordance with the design intent, including all aspects of radiological protection and safety; To certify that the commissioning programme has been satisfactorily completed; To transfer the responsibility for operation of the commissioned systems and/or plant to the operating group using a system of documents such as transfer certificates; To establish and implement procedures that ensure the orderly transfer of responsibilities for structures, systems and components from the construction group to the commissioning group and from the commissioning group to the operating group; To ensure that an opportunity is provided for operating personnel to gain plant experience, typically by utilizing the appropriate personnel, as necessary, for commissioning activities; To establish procedures for analysing the results of tests and for producing test reports and test certificates. Construction group The responsibilities of the construction group in relation to the commissioning process should include the following: 18